Single-neuronal predictions of others’ beliefs in humans

Human social behavior crucially depends on our ability to reason about others. This capacity for ‘theory of mind’ plays a vital role in social cognition because it allows us not only to form a detailed understanding of the hidden thoughts and beliefs of other individuals but to also understand that they may differ from our own(1–3). Although a number of areas in the human brain have been linked to social reasoning(4, 5) and its disruption across a variety of psychosocial disorders(6–8), the basic cellular mechanisms that underlie human theory of mind remain undefined. Using a rare opportunity to acutely record from single cells in the human dorsomedial prefrontal cortex, we discover neurons that reliably encode information about others’ beliefs across richly varying scenarios and that distinguish self- from other-belief related representations. By further following their encoding dynamics, we show how these cells represent the contents of the other’s beliefs and accurately predict whether they are true or false. We also show how they track inferred beliefs from another’s specific perspective and how their activities relate to behavioral performance. Together, these findings reveal a detailed cellular process in the human dorsomedial prefrontal cortex for representing another’s beliefs and identify candidate neurons that could support theory of mind.